Method and apparatus for band tuning in a communication device

ABSTRACT

A system that incorporates teachings of the present disclosure may include, for example, adjusting a tuning state of a matching network of the communication device, selecting a power offset from among a group of power offsets where the selected power offset is associated with a sub-band of operation of the communication device, and adjusting a value associated with a measured receive power or a transmit power of the communication device based on the selected power offset to generate an offset power value. Additional embodiments are disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and is a National Stage entry ofInternational Application Number PCT/US2012/049723, filed Aug. 6, 2012,which claims priority to U.S. Provisional Patent Application Ser. No.61/515,424 filed on Aug. 5, 2011, the disclosures of all of which arehereby incorporated by reference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to communication systems, andmore specifically to a method and apparatus for tuning of communicationdevices.

BACKGROUND

When tuning is implemented in a cellular handset, it is at times notpossible or otherwise difficult to achieve an ideal or desired solutiondue to different constraints in the realization of the tuning control inthe handset. These constraints can be due to a number of factors such asreal-time constraints in the handset software making it difficult toprogram the tuner with correct timing, programming interface for thetuner cannot be operated to achieve proper timing for the tuner, and/orfrequency, channel, or sub-band information not being available inreal-time to the tuning control software. The end result can be that thetuner is unable to be adequately synchronized with all transmit,receive, time slot, and/or frequency change events that occur in the RF.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an illustrative embodiment of a process for determiningpower offsets for a communication device;

FIG. 2 depicts an illustrative embodiment of a process that can be usedwith the process of FIG. 1 for adjusting power levels of thecommunication device;

FIG. 3 depicts an illustrative embodiment of a process for determiningpower offsets associated with a neighboring cell(s);

FIG. 4 depicts an illustrative embodiment of a process that can be usedwith the process of FIG. 3 for adjusting power levels of thecommunication device;

FIG. 5 depicts an illustrative embodiment of a look-up table that can beused by a communication device in accordance with one or more of theprocesses of FIGS. 1-4;

FIG. 6 depicts an exemplary diagrammatic representation of a machine inthe form of a computer system within which a set of instructions, whenexecuted, may cause the machine to perform any one or more of themethodologies disclosed herein.

FIG. 7 illustrates a coverage area for a wireless communication deviceincluding serving and neighbor cells;

FIGS. 8-10 illustrate power versus frequency data for various tuningschemes;

FIG. 11 depicts an illustrative embodiment of a communication device;

FIG. 12 depicts an illustrative embodiment of a portion of a transceiverof the communication device of FIG. 11;

FIGS. 13-14 depict illustrative embodiments of a tunable matchingnetwork of the transceiver of FIG. 12; and

FIGS. 15-16 depict illustrative embodiments of a tunable reactiveelement of the tunable matching network.

DETAILED DESCRIPTION

Radio band information is generally available or otherwise retrievablein communication devices, which provides the broadest definition ofwhere in the spectrum the handset is operating (e.g., transmitting). Incommunication systems (e.g., cellular systems), frequencies are commonlyallocated for usage in a block or range of frequencies. This block orrange of frequencies is commonly known as a radio band. Multiple radiobands can be present in any given cellular system, and in any geographiclocation there can be multiple cellular systems present.

A radio channel identifies a discrete set of frequencies in a cellularsystem that contains the downlink (from base station to the handset) anduplink (from handset to base station) radio signals. Downlink is alsoreferred to as Rx and uplink is also referred to as Tx. In most systems,such as Wideband Code Division Multiple Access (WCDMA), uplink anddownlink use separate frequencies that are separated by the duplexdistance, which is the number of Hz separating the uplink and downlinkpaths. For other systems, such as Time Division Long Term Evolution(TD-LTE), the uplink and downlink use the same frequency.

One or more of the exemplary embodiments can utilize radio bandinformation, including only radio band information in some embodiments,for antenna tuning. The exemplary embodiments can apply to various typesof communication devices, including wireless handsets operatingutilizing one or more of various communication protocols.

RF tuning based on limited information, such as only the radio band, cancreate a number of problems. In an ideal cellular system that employs RFtuning, the tuner would be set to match every frequency on which theradio receives or transmits, with the understanding that typically asingle antenna is used for both Rx and Tx which requires the RF tuner tochange tuning state as the RF signal on the antenna changes frequency.For half-duplex systems, such as GSM that would be for every Rx and Tx,including neighbor cells. In full-duplex systems, such as WCDMA whereboth Rx and Tx are present concurrently, the RF tuner has to change whenthe frequency changes for handoffs and neighbor cell monitoring, andadditionally the tuning state has to be a duplex setting for Rx and Txon a frequency between the Rx and Tx frequencies. Similar principles canbe applied to other existing wireless access technologies (e.g., UMTS,etc.) as well as future generation access technologies.

In order to perform RF tuning in such an ideal system, the entitycontrolling the tuner could require exact knowledge in real time of allrelevant information pertaining to operating the tuner, such as theradio timing, radio band, radio channel, RF duplex information, andtransmit state. Tuning based on limited information occurs when theentity controlling the tuner does not have all the information requiredto set the RF tuner to match an exact frequency at a given time. Forexample, real time channel information could be missing, in which casethe tuner control entity could set the RF tuner based on informationpertaining to the Radio Band only.

Transmit (Tx) and Receive (Rx) operations often cannot or are not tunedin real-time. This can result in or necessitate a broader duplex typetuning. Duplex tuning refers to where the tunable element for aparticular sub-band or radio channel is tuned to a frequency betweenuplink and downlink; one tuning state can be used for both Rx and Tx inthis case. In some systems that are full-duplex (concurrent uplink anddownlink, such as WCDMA), duplex tuning is commonly used. Other systemsthat are half-duplex (uplink and downlink are not concurrent, such asGSM), the tuner can be tuned for both Rx and Tx.

Sub-band describes a grouping of frequencies (e.g., radio channels)consisting of one or more radio channels. In tuning applications,sub-dividing a radio band into multiple sub-bands can provide theadvantage of being able to apply a particular tuning state to a small orsmaller range of radio channels. Sub-bands can be used in conjunctionwith storage and application of calibration data in cellular handsets,providing a compromise between accuracy and amount of storage needed tohold said calibration data.

An example of a radio band is the GSM 900 band, in which the uplinkfrequencies can occupy the range 880.0 to 915.0 MHz and the downlinkfrequencies can occupy the range 925.0 to 960.0 MHz. The duplex spacingcan be 45 MHz. The first channel can be channel 975 which has uplink at880.2 MHz and downlink at 915.2 MHz. The last channel can be channel 124which has uplink at 914.8 MHz and downlink at 959.8 MHz.

The GSM 900 band can, for example, be subdivided into 3 sub bands asfollows: Sub band 1 ranging from channel 975 to channel 1023 (48channels, 9.6 MHz wide), Sub Band 2 ranging from channel 0 to channel 66(66 channels, 13.2 MHz wide), and sub band 3 ranging from channel 67 tochannel 124 (57 channels, 11.4 MHz wide). This is an example of a radioband and sub-bands, and the present disclosure can include variousconfigurations of radio bands and sub-bands.

In one exemplary embodiment, duplex tuning can be provided for all typesof radio access technologies. Without channel or sub-band information,tuning may not be done on smaller frequency ranges than a radio band.Measurements at frequencies far from the center of the tuning band needto be corrected for the frequency response of the tuning network. Thesemeasurements may exhibit lower RF power levels, i.e., values that areerroneously low (as compared to error-free values) due to the frequencyresponse of the communication device.

Neighbor cells may or may not be in the radio band but since the radioband only refers to where the handset is transmitting, tuning may not bedone specifically to the neighbor. Neighbor cells may, when measured bythe handset, exhibit lower RF power levels, in particular when theNeighbor channel is in a different radio band than where the handset istransmitting. For the cellular system, this can result in poor handoverperformance in cell fringe areas negating the positive effect of antennatuning. As such any RF power level measured on any frequency away fromthe reference frequency of the tuner will diverge. If the tuner can betuned to said frequency, it removes the divergence. If the tuner cannotbe tuned to said frequency, the measured power will degrade.

In one exemplary embodiment, a method, to be performed by acommunication device, can include adjusting a tuning state of a matchingnetwork of the communication device. A tuning state is a setting in theRF tuner where the tunable elements are placed in a particular state tomatch a specific impedance. The tuning state can be adjusted (e.g., viachanging of values to match the specific desired impedance).

The method can include selecting a power offset from among a group ofpower offsets, where the selected power offset is associated with asub-band of operation of the communication device, and where the groupof power offsets is empirical data for power measurements for tuningstates at frequencies relative to a reference frequency of a radio band.The method can include adjusting, by the communication device, a valueassociated with a measured receive power or a transmit power of thecommunication device based on the selected power offset to generate anoffset power value. The offset is a value that is added to or subtractedfrom another value to produce a result. The adjusting is the act ofadding or subtracting.

In one exemplary embodiment, a wireless communication device can includea matching network and a controller coupled with the matching network.The controller can adjust a tuning state of the matching network. Thecontroller can select a power offset from among a group of poweroffsets, where the selected power offset is associated with a sub-bandof operation of the wireless communication device, and where the groupof power offsets is empirical data for power measurements for tuningstates at frequencies relative to a reference frequency of a radio band.The controller can adjust a value associated with a measured receivepower or a transmit power of the wireless communication device based onthe selected power offset to generate an offset power value.

In one exemplary embodiment, a non-transitory computer-readable storagemedium includes computer instructions which, responsive to beingexecuted by a processor of a communication device, cause the processorto perform operations comprising adjusting a tuning state of a matchingnetwork of the communication device. The computer instructions enableselecting a power offset from among a group of power offsets, where theselected power offset is associated with a sub-band of operation of thecommunication device, and where the group of power offsets is empiricaldata for power measurements for tuning states at frequencies relative toa reference frequency of a radio band. The computer instructions enableadjusting a value associated with a measured receive power or a transmitpower of the communication device based on the selected power offset togenerate an offset power value.

Referring generally to FIGS. 1 and 2, a set of offsets can be createdfor Tx and Rx power for any frequency relative to the chosen referencefrequency in the band. The offsets can be established via measurements.The power offsets can be empirical data for power measurements fortuning states at frequencies relative to a reference frequency of aradio band. The empirical data can be based on measured receive andtransmit powers for different tuning states of the matching network forthe reference frequency of the radio band and is based on measuredreceive and transmit powers for the different tuning states of thematching network for sub-band frequencies of the radio band.

The empirical data can also be done for various use cases and/or eachuse case. The use case can be of various types such as one or more ofantenna position, slider position, hands-free operation, speaker-phonemode, location of device, flip open state, slider out state, hand-heldoperation state, ear-piece speaker operation state, or a speaker-phoneoperation state.

In the handset, during normal operation, the Tx power offset and Rxpower offsets can be added to the actual Tx power or actual measured Rxpower compensate for the degradation away from the band referencefrequency. Use cases can be applied so that each band has a separate setof offsets for each use case.

Method 100 is a process that can be utilized for gathering the empiricaldata that enables offsetting measured receive power and/or transmitpower during operation of a communication device based on indexing ofsub-band frequencies. In step 110, tuning states of a variable matchingnetwork can be defined or otherwise implemented and Rx and Tx power canbe measured for a reference frequency of a radio band. In step 120, Rxand Tx power can be measured for each of the sub-bands utilizing thedefined tuning states for the band reference frequency. In step 130, theRx and Tx power empirical data can be stored as an offset from the bandreference frequency Rx and Tx power gathered in step 110. This processcan be repeated for various radio bands and each of the sub-bands ofeach of the radio bands. As described elsewhere herein, the offsetempirical data can be stored in a communication device for use duringoperation of the communication device, such as being stored in a look-uptable accessible by a controller or processor of the communicationdevice.

Method 200 is a process for adjusting power levels of a communicationdevice that can be performed by the communication device. In step 210,the communication device can perform tuning of a matching network thathas one or more variable reactance elements. For instance, theadjustment of the tuning state of the matching network can be based onvarious factors, including one or both of the radio band that thecommunication device is operating in and a use case(s) for thecommunication device. The term use case is used to distinguish differentantenna impedances that arise from external loading of the antenna, forexample placing a hand over the antenna would be referred to as “HandUse Case.” There are many possible use cases including one or more ofantenna position, slider position, hands-free operation, speaker-phonemode, location of device, flip open state, slider out state, hand-heldoperation state, ear-piece speaker operation state, or a speaker-phoneoperation state.

The tuning of the matching network can be performed using varioustechniques and components. For instance, the matching network caninclude one or more variable reactance elements, such as a voltagetunable dielectric capacitor, a semiconductor varactor, amicro-electro-mechanical systems (MEMS) varactor, a semiconductorswitched capacitor, and/or a MEMS switched capacitor. These elements canbe adjusted by the communication device, such as in a closed-loopfeedback process and/or an open-loop feedback process. The feedback caninclude the factors described above (e.g., radio band and/or usecase(s)) and/or other factors, including performance parameters of thecommunication device, such as transmit linearity, power amplifierefficiency, receive sensitivity, uplink or downlink throughput, totalradiated power and/or total isotropic sensitivity.

In step 220, in association with Tx operation, the Tx power offset canbe selected or retrieved from a group of power offsets (e.g., stored ina look-up table) based on the sub-band frequency at which thecommunication device is operating. The selected Tx power offset can beapplied to the Tx power setting to generate a modified or offset Txpower setting. In step 230, in association with Rx operation, the Rxpower offset can be selected or retrieved from the group of poweroffsets (e.g., stored in a look-up table) based on the sub-bandfrequency at which the communication device is operating. The selectedRx power offset can be applied to the measured Rx power to generate amodified or offset Rx power level.

The following is an example illustrating the application of the offsetsduring operation of the communication device whereby the Tx power offsetis, if intended, applied to the output power level, and the Rx poweroffset is applied to the measured receive power level. During Rx mode,we can assume that due to a tuner being tuned to an alternate frequencythan the Rx reference frequency, then the received power measured on theRx frequency is Pin and the loss in the tuner is Ploss. In thissituation, the actual input power is Pinact, such that Pin=Pinact−Ploss.To obtain a power measurement in proximity to the actual input power,the selected Rx power offset for the Rx frequency (Prxo) can be appliedto the measured receive power value to generate a measurement close tothe actual input power such that the measured powerPin=Pinact−Ploss+Prxo. If Prxo=Ploss then Pin=Pinact.

In this same example during Tx mode, we can assume that due to the tunerbeing tuned to an alternate frequency than the Tx reference frequencythen the intended output power setting on the Tx frequency is Pout andthe loss in the tuner is Ploss. The resulting actual output powerPtx=Pout−Ploss. Pout is the setting that is programmed in to the poweramplifier of the communication device. The selected Tx power offsetstored for the Tx frequency (Ptxo) can be applied to Pout resulting in anew output power setting Poutxo=Pout+Ptxo. The power amplifier can thenbe programmed to or implemented with Poutxo, such that the actual outputpower Ptx=Poutxo−Ploss=Pout+Ptxo−Ploss. In the case where Ptxo=Plossthen Ptx=Pout.

Other factors can be utilized in generating the modified or offsetmeasured receive power or transmit power levels so as to more closelyapproximate actual receive or transmit power.

Referring generally to FIGS. 3 and 4, a set of offsets can be createdfor the frequencies in each band (e.g., sub-bands) as well as neighborcell(s) (e.g., neighbor sub-bands) relative to the chosen referencefrequency in each band. Neighbor cells generally refer to frequencies inradio bands other than the band containing the reference frequency. Asub-band can refer to a single frequency or a set of frequencies withinthe radio band. The offsets can be created via measurements. This canalso be done for each use case. In the handset, during normal operation,the neighbor power offsets and sub-band offsets can be added tocompensate for the degradation away from the band reference frequency.Use cases can be applied so that each band has a separate set of offsetsfor each use case.

Method 300 is a process that can be utilized for gathering the empiricaldata that enables offsetting measured receive power and/or transmitpower during operation of a communication device based on indexing ofsub-band frequencies in association with neighboring cells. In step 310,tuning states of a variable matching network can be defined or otherwiseimplemented and Rx and Tx power can be measured for a referencefrequency of a radio band. In step 320, Rx power can be measured foreach of the sub-bands of neighboring cells utilizing the defined tuningstates for the band reference frequency. In step 330, the Rx powerempirical data can be stored as an offset from the band referencefrequency Rx and Tx power gathered in step 310. This process can berepeated for various radio bands and each of the neighboring cellsub-bands. As described elsewhere herein, the offset empirical data canbe stored in a communication device for use during operation of thecommunication device, such as being stored in a look-up table accessibleby a controller or processor of the communication device, including inconjunction with a handover operation between network cells.

Method 400 is a process for adjusting power levels of a communicationdevice that can be performed by the communication device. In step 410,the communication device can perform tuning of a matching network thathas one or more variable reactance elements, including tuning based onvarious factors, such as one or both of the radio band that thecommunication device is operating in and a use case(s) for thecommunication device.

In step 420, in association with Rx operation, the Rx power offset canbe selected or retrieved from the group of power offsets (e.g., storedin a look-up table) based on the sub-band frequency at which thecommunication device is operating. The selected Rx power offset can beapplied to the measured Rx power of a neighboring cell to generate amodified or offset Rx power level.

Referring generally to FIG. 5, a look-up table 500 that can be utilizedby a communication device is shown. The look-up table 500 can be storedin a memory of the communication device and accessed during operation(such as a wireless voice communication or wireless data communication)to enable control and adjustment of measured receive power and/ortransmit power levels. The look-up table 500, which can be generatedaccording to one or both of methods 100 and 300, can be provisioned intothe wireless communication device. The look-up table 500 can includevarious categorizations for empirical data including use cases and radiobands. The look-up table 500 can also include tuning, sub-band offsetsand neighbor band settings, as well as neighbor band offsets. In oneembodiment, the offset data can be stored per sub-band to save memoryresources of the communication device.

As an example illustrated in FIG. 5, a communication device, inconjunction with a handover operation between a serving cell and aneighboring cell, can utilize a current use case (such as use case 1)and a current radio band of the serving cell (such as Radio Band GSM900) to index via table 500 to a radio band of the neighboring cell(such as Radio Band GSM 1800) and further index to power offset dataassociated with a sub-band frequency of the neighboring cell radio band.In this example, the empirical data for the power offsets includes Rxoffset data for neighboring cell sub-bands 0-n. The empirical data canbe utilized by the communication device for adjusting the measuredreceive power level and for making radio resource decisions based on theadjusted level and/or providing the adjusted level to a network elementwhich makes a radio resource decision, such as a handover decision.

FIG. 6 depicts an exemplary diagrammatic representation of a machine inthe form of a computer system 600 within which a set of instructions,when executed, may cause the machine to perform any one or more of themethodologies discussed above. In some embodiments, the machine operatesas a standalone device. In some embodiments, the machine may beconnected (e.g., using a network) to other machines. In a networkeddeployment, the machine may operate in the capacity of a server or aclient user machine in server-client user network environment, or as apeer machine in a peer-to-peer (or distributed) network environment. Themachine can be representative of communication device 1100 or a portionthereof.

The machine may comprise a server computer, a client user computer, apersonal computer (PC), a tablet PC, a laptop computer, a desktopcomputer, a control system, a network router, switch or bridge, or anymachine capable of executing a set of instructions (sequential orotherwise) that specify actions to be taken by that machine. It will beunderstood that a device of the present disclosure includes broadly anyelectronic device that provides voice, video or data communication.Further, while a single machine is illustrated, the term “machine” shallalso be taken to include any collection of machines that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein.

The computer system 600 may include a processor 602 (e.g., a centralprocessing unit (CPU), a graphics processing unit (GPU, or both), a mainmemory 604 and a static memory 606, which communicate with each othervia a bus 608. The computer system 600 may further include a videodisplay unit 610 (e.g., a liquid crystal display (LCD), a flat panel, asolid state display, or a cathode ray tube (CRT)). The computer system600 may include an input device 612 (e.g., a keyboard), a cursor controldevice 614 (e.g., a mouse), a disk drive unit 616, a signal generationdevice 618 (e.g., a speaker or remote control) and a network interfacedevice 620.

The disk drive unit 616 may include a machine-readable medium 622 onwhich is stored one or more sets of instructions (e.g., software 624)embodying any one or more of the methodologies or functions describedherein, including those methods illustrated above. The instructions 624may also reside, completely or at least partially, within the mainmemory 604, the static memory 606, and/or within the processor 602during execution thereof by the computer system 600. The main memory 604and the processor 602 also may constitute machine-readable media.

Dedicated hardware implementations including, but not limited to,application specific integrated circuits, programmable logic arrays andother hardware devices can likewise be constructed to implement themethods described herein. Applications that may include the apparatusand systems of various embodiments broadly include a variety ofelectronic and computer systems. Some embodiments implement functions intwo or more specific interconnected hardware modules or devices withrelated control and data signals communicated between and through themodules, or as portions of an application-specific integrated circuit.Thus, the example system is applicable to software, firmware, andhardware implementations.

In accordance with various embodiments of the present disclosure, themethods described herein are intended for operation as software programsrunning on a computer processor. Furthermore, software implementationscan include, but not limited to, distributed processing orcomponent/object distributed processing, parallel processing, or virtualmachine processing can also be constructed to implement the methodsdescribed herein.

The present disclosure contemplates a machine readable medium containinginstructions 624, or that which receives and executes instructions 624from a propagated signal so that a device connected to a networkenvironment 626 can send or receive voice, video or data, and tocommunicate over the network 626 using the instructions 624. Theinstructions 624 may further be transmitted or received over a network626 via the network interface device 620.

While the machine-readable medium 622 is shown in an example embodimentto be a single medium, the term “machine-readable medium” should betaken to include a single medium or multiple media (e.g., a centralizedor distributed database, and/or associated caches and servers) thatstore the one or more sets of instructions. The term “machine-readablemedium” shall also be taken to include any medium that is capable ofstoring, encoding or carrying a set of instructions for execution by themachine and that cause the machine to perform any one or more of themethodologies of the present disclosure.

The term “machine-readable medium” shall accordingly be taken toinclude, but not be limited to: solid-state memories such as a memorycard or other package that houses one or more read-only (non-volatile)memories, random access memories, or other re-writable (volatile)memories; magneto-optical or optical medium such as a disk or tape;and/or a digital file attachment to e-mail or other self-containedinformation archive or set of archives is considered a distributionmedium equivalent to a tangible storage medium. Accordingly, thedisclosure is considered to include any one or more of amachine-readable medium or a distribution medium, as listed herein andincluding art-recognized equivalents and successor media, in which thesoftware implementations herein are stored.

Referring to FIG. 7, a coverage area for a wireless communication deviceis illustrated in which there is a serving cell and multiple neighboringcells that operate according to various radio bands and channels. InFIG. 8, relative power (depicted in −dB) is illustrated when the tunerof the communication device is set at channel a of radio band A (servingcell of FIG. 7). In FIG. 9, relative power (depicted in −dB) isillustrated when the tuner of the communication device is set at channely of radio band C (neighbor cell of FIG. 7). As FIGS. 8-9 illustrate,tuning to the serving cell only and not to neighbor cells can result inundesired conditions, including call drops and reduced data rates.

FIG. 10 illustrates relative power (depicted in −dB) when the tuner ofthe communication device is tuned to each of the correspondingfrequencies. By tuning to the neighboring cells as well, thecommunication device can avoid a neighbor signal strength beingperceived lower than nominal strength which would cause thecommunication device to report too low neighbors to the network andwhich would cause network to delay handover command to the communicationdevice until reported neighbor strength is above handover threshold. Byincluding the neighboring cells as a factor in the tuning of thematching network, the communication device can avoid a delayed handover.Avoiding a delayed handover can be beneficial as it may force thecommunication device to use a serving channel for a longer than desiredtime period at lower signal quality levels, which would reduce the datarate to maintain the link margin. As shown in FIG. 10, the ResultingResponse is the peak relative power as the tuning frequency is sweptthrough the radio band(s).

FIG. 11 depicts an exemplary embodiment of a communication device 1100which can implement the power level adjustments via empirical offsetdata as described with respect to FIGS. 1-10. The communication device1100 can comprise a wireless transceiver 1102 (herein having independenttransmit and receive sections and having one or more antennas 1145 (twoof which are shown in this example)), a user interface (UI) 1104, apower supply 1114, and a controller 1106 for managing operationsthereof. The wireless transceiver 1102 can utilize short-range orlong-range wireless access technologies such as Bluetooth, WiFi, DigitalEnhanced Cordless Telecommunications (DECT), or cellular communicationtechnologies, just to mention a few. Cellular technologies can include,for example, CDMA-1X, WCDMA, UMTS/HSDPA, GSM/GPRS, TDMA/EDGE, EV/DO,WiMAX, and next generation cellular wireless communication technologiesas they arise.

The UI 1104 can include a depressible or touch-sensitive keypad 1108with a navigation mechanism such as a roller ball, joystick, mouse, ornavigation disk for manipulating operations of the communication device1100. The keypad 1108 can be an integral part of a housing assembly ofthe communication device 1100 or an independent device operably coupledthereto by a tethered wireline interface (such as a flex cable) or awireless interface supporting for example Bluetooth. The keypad 1108 canrepresent a numeric dialing keypad commonly used by phones, and/or aQwerty keypad with alphanumeric keys. The UI 1104 can further include adisplay 1110 such as monochrome or color LCD (Liquid Crystal Display),OLED (Organic Light Emitting Diode) or other suitable display technologyfor conveying images to an end user of the communication device 1100. Inan embodiment where the display 1110 is a touch-sensitive display, aportion or all of the keypad 1108 can be presented by way of thedisplay.

The power supply 1114 can utilize common power management technologies(such as replaceable batteries, supply regulation technologies, andcharging system technologies) for supplying energy to the components ofthe communication device 1100 to facilitate portable applications. Thecontroller 1106 can utilize computing technologies such as amicroprocessor and/or digital signal processor (DSP) with associatedstorage memory such a Flash, ROM, RAM, SRAM, DRAM or other liketechnologies.

The communication device 1100 can utilize an on-antenna tuning element1150 (and/or an independent matching network), which can be directlyconnected with the radiating element(s), including high band (HB) andlow band (LB) radiating elements and/or a portion of the radiatingelements. Tuning elements can be a number of components in a number ofdifferent configurations, including variable capacitors such aselectrically tunable capacitors, although other tunable elements arealso contemplated by the present disclosure including a semiconductorvaractor, a micro-electro-mechanical systems (MEMS) varactor, a MEMSswitched reactive element, a piezoelectric component or a semiconductorswitched reactive element.

FIG. 12 depicts an illustrative embodiment of a portion of the wirelesstransceiver 1102 of the communication device 1100 of FIG. 11. In GSMapplications, the transmit and receive portions of the transceiver 1102can include common amplifiers 1201, 1203 coupled to a tunable matchingnetwork 1202 and an impedance load 1206 by way of a switch 1204. Theload 1206 in the present illustration can be an antenna as shown in FIG.11 (herein antenna 1206). A transmit signal in the form of a radiofrequency (RF) signal (Tx) can be directed to the amplifier 1201 whichamplifies the signal and directs the amplified signal to the antenna1206 by way of the tunable matching network 1202 when switch 1204 isenabled for a transmission session. The receive portion of thetransceiver 1102 can utilize a pre-amplifier 1203 which amplifiessignals received from the antenna 1206 by way of the tunable matchingnetwork 1202 when switch 1204 is enabled for a receive session. Otherconfigurations of FIG. 12 are possible for other types of cellularaccess technologies such as CDMA. These undisclosed configurations arecontemplated by the present disclosure. As explained above, the transmitpower can be amplified based on the modified offset value which isdetermined based on empirical data such as included in look-up table500.

FIGS. 13-14 depict illustrative embodiments of the tunable matchingnetwork 1202 of the transceiver 1102 of FIG. 12. In one embodiment, thetunable matching network 1202 can comprise a control circuit 1302 and atunable reactive element 1310. The control circuit 1302 can comprise aDC-to-DC converter 1304, one or more digital to analog converters (DACs)1306 and one or more corresponding buffers 1308 to amplify the voltagegenerated by each DAC. The amplified signal can be fed to one or moretunable reactive components 1504, 1506 and 1508 such as shown in FIG.15, which depicts a possible circuit configuration for the tunablereactive element 1310. In this illustration, the tunable reactiveelement 1310 includes three tunable capacitors 1504-1508 and an inductor1502 with a fixed inductance. Other circuit configurations are possible,and thereby contemplated by the present disclosure.

The tunable capacitors 1504-1508 can each utilize technology thatenables tunability of the capacitance of said component. One embodimentof the tunable capacitors 1504-1508 can utilize voltage or currenttunable dielectric materials such as a composition of barium strontiumtitanate (BST). An illustration of a BST composition is the Parascan®Tunable Capacitor. In another embodiment, the tunable reactive element1310 can utilize semiconductor varactors. Other present or nextgeneration methods or material compositions that can support a means fora voltage or current tunable reactive element are contemplated by thepresent disclosure.

The DC-to-DC converter 1304 can receive a power signal such as 3 Voltsfrom the power supply 1114 of the communication device 1100 in FIG. 11.The DC-to-DC converter 1304 can use common technology to amplify thispower signal to a higher range (e.g., 30 Volts) such as shown. Thecontroller 1106 can supply digital signals to each of the DACs 1306 byway of a control bus of “n” or more wires to individually control thecapacitance of tunable capacitors 1504-1508, thereby varying thecollective reactance of the tunable matching network 1202. The controlbus can be implemented with a two-wire common serial communicationstechnology such as a Serial Peripheral Interface (SPI) bus. With an SPIbus, the controller 1106 can submit serialized digital signals toconfigure each DAC in FIG. 13 or the switches of the tunable reactiveelement 1404 of FIG. 14. The control circuit 1302 of FIG. 13 can utilizecommon digital logic to implement the SPI bus and to direct digitalsignals supplied by the controller 1106 to the DACs.

In another embodiment, the tunable matching network 1202 can comprise acontrol circuit 1402 in the form of a decoder and a tunable reactiveelement 1404 comprising switchable reactive elements such as shown inFIG. 16. In this embodiment, the controller 1106 can supply the controlcircuit 1402 signals via the SPI bus which can be decoded with commonBoolean or state machine logic to individually enable or disable theswitching elements 1602. The switching elements 1602 can be implementedwith semiconductor switches or micro-machined switches, such as utilizedin micro-electromechanical systems (MEMS). By independently enabling anddisabling the reactive elements (capacitor or inductor) of FIG. 16 withthe switching elements 1602, the collective reactance of the tunablereactive element 1404 can be varied.

The tunability of the tunable matching networks 1202, 1204 provides thecontroller 1106 a means to optimize, increase or otherwise adjust(including decreasing in a compromise) performance parameters of thetransceiver 1102 such as, for example, but not limited to, transmitterpower, transmitter efficiency, receiver sensitivity, power consumptionof the communication device, a specific absorption rate (SAR) of energyby a human body, frequency band performance parameters, and so on.

Various tuning techniques can be utilized in the exemplary embodimentsin conjunction with the power control techniques described herein. Forexample, in a time division multiplexed (TDM) system in which thetransmitter and the receiver operate at different frequencies but onlyoperate in their respective time slots (i.e., transmit time slot andreceive time slot), this can be accomplished by identifying an optimaltuning for the transmitter and then adding an empirically derivedadjustment to the tuning circuits in receive mode. As another example,in a frequency division multiplexed (FDM) system in which thetransmitter and receiver operate simultaneously and at differentfrequencies, this can be accomplished by identifying a target operationfor the transmitter, and then adjusting the tuning circuits first to thetarget value for the transmitter and then adjusting the values toapproach a compromised value proximate to an equal or desired targetvalue for the receiver. In one embodiment, a predetermined relationship,(e.g., an offset, scaling factor, translation or other change ormodification) can be applied to the adjustments of the variablecomponents when switching from the transmit mode to the receive mode.This translation can be a function of the values obtained whileadjusting during the transmit time slot. The translation can then beremoved upon return to the transmitter mode and the adjustment processis resumed. In one embodiment, because any frequency offset between thetransmit signal and the receive signal is known, an adjustment ormodification of the setting of the matching network in the form of atranslation or some other function can be applied to the matchingnetwork during the receive time slot. In another embodiment, theadjustment can be performed in multiple steps if the transmission andreception frequencies are far apart.

In another embodiment and in conjunction with the power controltechniques described herein, a Figure of Merit can be utilized that notonly incorporates the transmit metrics, but also incorporates an elementto attain a compromise between optimal transmitter and optimal receiveroperation. This can be accomplished by identifying a target operationgoal, such as a desired transmitter and receiver reflection loss andthen identifying an operational setting that is a close compromisebetween the two. This embodiment thus can incorporate not onlytransmitter metrics but also tuning circuit settings or preferences intothe algorithm. The tuning preferences can be empirically identified toensure the desired operation.

The illustrations of embodiments described herein are intended toprovide a general understanding of the structure of various embodiments,and they are not intended to serve as a complete description of all theelements and features of apparatus and systems that might make use ofthe structures described herein. Many other embodiments will be apparentto those of skill in the art upon reviewing the above description. Otherembodiments may be utilized and derived therefrom, such that structuraland logical substitutions and changes may be made without departing fromthe scope of this disclosure. Figures are also merely representationaland may not be drawn to scale. Certain proportions thereof may beexaggerated, while others may be minimized. Accordingly, thespecification and drawings are to be regarded in an illustrative ratherthan a restrictive sense.

Such embodiments of the inventive subject matter may be referred toherein, individually and/or collectively, by the term “invention” merelyfor convenience and without intending to voluntarily limit the scope ofthis application to any single invention or inventive concept if morethan one is in fact disclosed. Thus, although specific embodiments havebeen illustrated and described herein, it should be appreciated that anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description. Portions of the exemplaryembodiments can be combined, including combining components fromdifferent embodiment and/or combing steps from different methods.

The Abstract of the Disclosure is provided with the understanding thatit will not be used to interpret or limit the scope or meaning of theclaims. In addition, in the foregoing Detailed Description, it can beseen that various features are grouped together in a single embodimentfor the purpose of streamlining the disclosure. This method ofdisclosure is not to be interpreted as reflecting an intention that theclaimed embodiments require more features than are expressly recited ineach claim. Rather, as the following claims reflect, inventive subjectmatter lies in less than all features of a single disclosed embodiment.Thus the following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separately claimedsubject matter.

What is claimed is:
 1. A method, to be performed by a communicationdevice, comprising: adjusting, by the communication device, a tuningstate of a matching network of the communication device; determining, bythe communication device, a use case of the communication device;selecting, by the communication device, a power offset from among agroup of power offsets according to the use case and according to asub-band of operation of a neighboring cell for the communicationdevice, the group of power offsets being empirical data for powermeasurements for tuning states at frequencies relative to a referencefrequency of a radio band for a serving cell; measuring, by thecommunication device, a received power of a signal at a neighboring cellfrequency received by the communication device from the neighboring cellto determine a measured receive power value; determining, by thecommunication device, an offset power value by adjusting the measuredreceive power value according to the selected power offset, whereby thematching network is tuned to the reference frequency; and transmitting,from the communication device to a network element, the offset powervalue to cause the network element to make a radio resource decision forthe communication device based on the offset power value and not basedon the measured receive power value, wherein the radio resource decisionis a handover decision associated with the neighboring cell, and whereinthe decision is based at least in part on whether the offset power valuecorresponds to a perceived neighbor signal strength above a handoverthreshold.
 2. The method of claim 1, wherein in accordance with theradio resource decision, a handover delay is avoided.
 3. The method ofclaim 1, wherein the adjusting of the tuning state of the matchingnetwork is based on a closed-loop process utilizing feedback thatincludes a power amplifier efficiency.
 4. The method of claim 1, whereinthe empirical data is based on measured receive power for differenttuning states of the matching network for the reference frequency of theradio band and is based on measured receive power for the differenttuning states of the matching network for sub-band frequencies of theradio band.
 5. The method of claim 1, wherein the group of power offsetsare stored in a look-up table of a memory of the communication device.6. The method of claim 5, wherein the look-up table is categorized byradio bands, sub-bands, neighbor radio bands and neighbor sub-bands. 7.The method of claim 5, wherein the adjusting of the tuning state of thematching network comprises adjusting a reactance of a voltage tunabledielectric capacitor.
 8. The method of claim 7, wherein the use case isa physical state of the communication device.
 9. The method of claim 1,wherein the adjusting of the tuning state is based on a sub-band ofoperation of the communication device.
 10. The method of claim 1,wherein the adjusting of the tuning state is based on the use case ofthe communication device.
 11. The method of claim 1, wherein the usecase corresponds to at least one of a flip open state, a slider outstate, a hand's free operation state, a hand-held operation state, anear-piece speaker operation state, or a speaker-phone operation state.12. The method of claim 1, wherein the adjusting of the tuning state ofthe matching network comprises adjusting a reactance of one or more of asemiconductor varactor, a micro-electro-mechanical systems (MEMS)varactor, a semiconductor switched capacitor, or a MEMS switchedcapacitor.
 13. A wireless communication device comprising: a matchingnetwork; and a controller coupled with the matching network, wherein thecontroller: adjusts a tuning state of the matching network; selects apower offset from among a group of power offsets according to a sub-bandof operation of a neighboring cell of the wireless communication device,the group of power offsets being empirical data for power measurements;measures a received power of a signal at a neighboring cell frequencyreceived by the wireless communication device from neighboring cell todetermine a measured received power value; determines an offset powervalue by adjusting the measured receive power value according to theselected power offset, whereby the matching network is tuned to areference frequency; and transmits, to a network element, the offsetpower value to cause the network element to make a radio resourcedecision for the wireless communication device based on the offset powervalue and not based on the measured receive power value, wherein theradio resource decision is a handover decision associated with theneighboring cell, and wherein the decision is based at least in part onwhether the offset power value corresponds to a perceived neighborsignal strength above a handover threshold.
 14. The wirelesscommunication device of claim 13, wherein the controller adjusts thetuning state of the matching network based on a closed-loop processutilizing feedback that includes a power amplifier efficiency.
 15. Thewireless communication device of claim 13, wherein the empirical data isfor tuning states at frequencies relative to the reference frequency,the reference frequency being within a radio band of a serving cell,wherein the empirical data is based on measured receive power fordifferent tuning states of the matching network for the referencefrequency of the radio band and is based on measured receive power forthe different tuning states of the matching network for sub-bandfrequencies of the radio band.
 16. The wireless communication device ofclaim 13, comprising a memory, wherein the group of power offsets arestored in a look-up table in the memory, and wherein the look-up tableis categorized by one or more of radio bands, sub-bands, neighbor radiobands, neighbor sub-bands or use cases.
 17. The wireless communicationdevice of claim 16, wherein the controller determines a physical usecase of the wireless communication device and selects the power offsetbased on the physical use case.
 18. The wireless communication device ofclaim 13, wherein the controller adjusts the tuning state of thematching network based on at least one of the sub-band of operation ofthe wireless communication device or a use case of the wirelesscommunication device, and wherein the matching network comprises one ormore of a voltage tunable dielectric capacitor, a semiconductorvaractor, a micro-electro-mechanical systems (MEMS) varactor, asemiconductor switched capacitor, or a MEMS switched capacitor.
 19. Anon-transitory computer-readable storage medium comprising computerinstructions which, responsive to being executed by a processor of acommunication device, cause the processor to perform operationscomprising: adjusting a tuning state of a matching network of thecommunication device; selecting a power offset from among a group ofpower offsets according to a sub-band of operation of a neighboring cellof the communication device, the group of power offsets being empiricaldata for power measurements; measuring a received power of a signal at aneighboring cell frequency received by the communication device from theneighboring cell to determine a measured receive power value;determining an offset power value by adjusting the measured receivepower value according to the selected power offset, whereby the matchingnetwork is tuned to a reference frequency; and transmitting, to anetwork element, the offset power value to cause the network element tomake a radio resource decision for the communication device based on theoffset power value and not based on the measured receive power value,wherein the radio resource decision is a handover decision associatedwith the neighboring cell, and wherein the decision is based at least inpart on whether the offset power value corresponds to a perceivedneighbor signal strength above a handover threshold.
 20. Thenon-transitory computer-readable storage medium of claim 19, wherein theempirical data is for tuning states at frequencies relative to thereference frequency, the reference frequency being within a radio bandof a serving cell, wherein the empirical data is based on measuredreceive power for different tuning states of the matching network forthe reference frequency of the radio band and is based on measuredreceive power for the different tuning states of the matching networkfor sub-band frequencies of the radio band, and wherein the group ofpower offsets are stored in a look-up table that is categorized by oneor more of radio bands, sub-bands, neighbor radio bands, neighborsub-bands or use cases.